Encapsulation of urease in double‐layered hydrogels of macroporous poly(2‐hydroxyethyl methacrylate) core and poly(ethylene oxide) outer layer: fabrication and biosensing properties

Double‐layered hydrogels of super‐macroporous poly(2‐hydroxyethyl methacrylate) (PHEMA) cryogel core and poly(ethylene oxide) (PEO) hydrogel outer layer for encapsulation of the enzyme urease were constructed. The enzyme was entrapped into the pores of PHEMA cryogel by soaking and then the core was covered with a PEO layer. The leaking of urease from the core was prevented when the density of the PEO network was increased by incorporation of the crosslinking agent, poly(ethylene glycol) diacrylate. The hybrid system exhibited a nearly constant enzyme activity with time and maintained its structural integrity after several reactions of hydrolysis of urea. The potential of double‐layered hydrogels containing urease for establishment of water pollution with copper was investigated as well. Copyright © 2011 Society of Chemical Industry